The capability to measure atom densities of1H,2H, and4He in HgCdTe and CdTe above about 1018cm−3in background‐subtracted cesium beam secondary ion mass spectrometry profiles has been demonstrated using ion implantation and implanted fluences. Range parameters are determined for ion energies between 150 and 300 keV. Projected ranges for1H are slightly greater than those for2H in both HgCdTe and CdTe. Hydrogen ion ranges are about 0.75 &mgr;m/100 keV of energy in both materials, and the third moment of the depth distributions is about −2.1.